A dry contact monitoring manner is generally used in a station power monitoring system. Dry contacts are classified into an input dry contact and an output dry contact. The input dry contact, for example, a switch or a button, is used to receive an external Boolean signal, and the output dry contact is used to implement alarm output, association control, or the like.
In an existing dry contact monitoring circuit, an input dry contact monitoring circuit and an output dry contact monitoring circuit are mutually independent. That is, the input dry contact monitoring circuit includes a configuration interface, a protection circuit, and a detection circuit, where the detection circuit is configured to detect a status of a signal received by an input dry contact connected to the configuration interface; the output dry contact monitoring circuit includes a configuration interface, a protection circuit, a relay, a control circuit, and a detection circuit, where the detection circuit is configured to detect a working status of the relay, and further determine a working status of an output dry contact connected to the configuration interface.
In the foregoing dry contact monitoring circuit, the input dry contact monitoring circuit and the output dry contact monitoring circuit use different configuration interfaces. When the output dry contact monitoring circuit configured in a system cannot satisfy a user requirement, the configuration interface in the input dry contact monitoring circuit cannot be configured as an output dry contact. When the input dry contact monitoring circuit configured in the system cannot satisfy a user's use requirement, the configuration interface in the output dry contact monitoring circuit cannot be configured as an input dry contact. Instead, an output dry contact monitoring circuit or an input dry contact monitoring circuit that satisfies a user requirement needs to be re-added, resulting in poor configurability of the system.